. >> the focus in court again today was this dramatic call on 911 from the knights trayvon martin died. witnesses were called back to look at the response the father of trayvon martin said when asked who was screaming for help in the background of that call. response?. martin's >> that it was not his son. >> you said he put his head down? >> yes, and he was crying. he had his face in tissues. >> he also appeared to wipe away tears during today's testimony. george zimmerman has told police it is his voice the night he shot and killed martin. he is pleading not guilty of second-degree murder, saying he acted in self-defense. the recording was at the center of the first full day of the presentation from the defense, including testimony from a string of co-workers and friends, each asking the same question about the audio recording and giving the same answer. >> yes, i thought it was george. >> yes, george. >> i thought it was him a common george zimmerman. >> there was strong support of george zimmerman. some donated to his defense fund, and some wrote a book, saying they will donate the